Jared Wein — Bug 1328805 - Enable the no-cond-assign rule for eslint and fix the six resulting errors mostly by wrapping the assignment with parentheses to explicitly state that the assignment is intentional with exception for advanced.js where assignment was not intended. r=mossop

Jared Wein — Bug 1328800 - Enable the no-sparse-arrays rule for eslint and change the two instances of it to use 'undefined' instead of a sparse array since the test will still be fine either way. r=mak